1. Field of the Invention
The present invention relates to a vehicle driver's fatigue evaluating method for evaluating a degree of fatigue of a driver sitting on a seat of a vehicle such as a passenger vehicle, commercial vehicle or a bus, and to a vehicle seat evaluating method and vehicle seat evaluating apparatus using this vehicle driver's fatigue evaluating method.
2. Description of Related Art
In order to improve comfort in vehicles, development is desired of seats that cause little fatigue after a long sitting. To reduce the fatigue of the waist in particular is effective for relieving the fatigue of the whole body for the driver sitting on the seat.
The vehicle driver's fatigue evaluating method includes a method in which a subject is asked to enter a feeling of seating and a feeling of fatigue (especially a feeling of fatigue of the waist) on an evaluation sheet, and a method in which the fatigue of the waist of a subject is evaluated by detecting the myoelectric potential of the waist, both after the subject is actually seated on a seat for a long time.
As described in the prior art, a problem of low reliability occurs with the method in which the subject is asked to enter a feeling of seating and a feeling of fatigue on an evaluation sheet. This is because the subject's subjectivity tends to influence the evaluation of the feeling of seating and the feeling of fatigue (especially a feeling of fatigue of the waist), and an objective and quantitative evaluation of the fatigue of the driver sitting on a seat is impossible.
In the method in which the fatigue of the waist of a subject is evaluated by detecting the myoelectric potential of the waist, the myoelectric potential detected is prone to noise (spike noise, i.e. noise of very small pulse width resulting from switching operations). The fatigue of the driver sitting on a seat cannot be evaluated properly only by detecting the myoelectric potential of the subject's waist. Further, its validity is not positive with respect to the existence of correlation between the fatigue of the driver sitting on the seat and the myoelectric potential of the subject's waist.
The object of the present invention is to provide a highly reliable vehicle driver's fatigue evaluating method capable of quantitatively calculating a degree of fatigue of a driver seated on a seat, and to provide a highly reliable vehicle seat evaluating method and vehicle seat evaluating apparatus using this vehicle driver's fatigue evaluating method.